As one example, in Japan, as a result of a rise in living standards, an improvement in hygienic environment and a rise in level of medical treatment along with rapid economic growth after World War II, Japan is entering into an aged society, more specifically, a super-aged society in which a population aging rate, i.e., a ratio of a population of persons over 65 to a total population, is greater than 21%. Further, there are forecasts that, in 2020, the population of persons over 65 will reach about 34.56 million in a total population of about 124.11 million, while, in 2005, the population of persons over 65 was about 25.56 million in a total population of about 127.65 million.
In such an aged society, it is forecast that the number of persons requiring nursing care due to disease, injury and the like becomes greater than that in a non-aged or normal society.
Such a person requiring nursing care enters or gets a place on a facility such as a hospital or a welfare facility for the aged (e.g., in Japan, a respite care facility for the aged, a nursing home for the aged or a special nursing home for the aged), and receives nursing care. This type of facility such as a hospital or a welfare facility for the aged is generally equipped with a so-called nurse call system to be used when a person requiring nursing care calls a nurse or a care worker to receive nursing care. The facility is also equipped with a device for monitoring a state of the person requiring nursing care, as needed basis.
One example of the nurse call system is disclosed in the following Patent Literature 1. A nurse call system disclosed in the Patent Literature 1 includes: an in-bed child unit installed in each bed in each hospital room of a hospital or a welfare facility for the aged, and configured to allow a person receiving nursing care to call a nurse, and a plate-shaped child unit detachably connected to the in-bed child unit; a call-corresponding camera (30a, 30b, - - - ) installed in each hospital room and configured to take an image of the person; a nurse call parent unit installed in a nurse center and configured to detect a call from the in-bed child unit and inform a nurse of the call so as to allow the nurse who acknowledged the call to establish communication, wherein the nurse call parent unit is connected with an external call-corresponding monitor for outputting the image of the subject taken by the call-corresponding camera, and wherein the external call-corresponding monitor is connected with the call-corresponding camera and configured to be controlled by the nurse call parent unit when the nurse call parent unit detects the call from the in-bed child unit; a storage unit storing therein a camera selection table for selecting one of a plurality of the call-corresponding cameras which has a camera number corresponding to a child unit number of the plate-shaped child unit connected to the in-bed child unit as a source of the call; and a camera drive circuit for reading, from the storage section, the camera number corresponding to the child unit number of the plate-shaped child unit connected to the in-bed child unit as the source of the call, and driving the call-corresponding camera having the read camera number to output an image of the person to the external call-corresponding monitor.
One example of a system for monitoring a state of the person requiring nursing care is disclosed in the following Patent Literature 2. A system disclosed in the Patent Literature 2 is a monitoring system for monitoring an abnormal state of a target body, which includes: a physiological signal monitor configured to monitor a physiological signal; a processor configured to receive an output signal from the physiological signal monitor and detect the occurrence of abnormality in the physiological signal; and a detection sub-system coupled to receive an output signal from the processor, and configured to operate in a selected detection mode for monitoring a movement of the target body, based on the output signal from the processor, so as to detect the abnormal state. In order to perform an initial determination about a possibility of fall-over of a user, the physiological signal is continuously measured in view of a causal factor of the fall-over (see, for example, paragraph [0021]). More specifically, the physiological signal is heart rate, blood flow pulsation, blood pressure, ECG, EMG or SpO2 (see, for example, paragraph [0026]). The Patent Literature 2 also describes that, in order to detect abnormality in a target body, the monitoring system may further include an accelerator meter for detecting an acceleration of the target body, or an inclination sensor for measuring a level of inclination of the target body, and that the abnormality in the target body may be detected from an output signal from the accelerator meter or the inclination sensor, while taking into account the physiological signal (see, for example, paragraph [0029]).
Meanwhile, in the nurse call system disclosed in the Patent Literature 1, a nurse can view an image of a person receiving nursing care (one example of a subject) taken by the call-corresponding camera, on the external call-corresponding monitor, so that it becomes possible to observe a state of the person without going drown to a room of the person. However, as long as no call (nurse call) is generated from the person based on an operation of the in-bed child unit by the person, an image of the person taken by the call-corresponding camera is never output, so that it is impossible to view the image of the person on the external call-corresponding monitor. As long as no call is generated from the person based on an operation of the in-bed child unit by the person, a nurse cannot know whether or not the person requires nursing care, in the first place.
The monitoring system disclosed in the Patent Literature 2 is capable of detecting fall-over of a target body (one example of a subject). However, the monitoring system disclosed in the Patent Literature 2 is intended to detect fall-over of the target body to thereby select a specific detection mode so as to achieve power saving. That is, the monitoring system disclosed in the Patent Literature 2 is not configured to issue a notification indicative of fall-over of the target body to outside so as to inform a nurse or the like of the fall-over of the target body. Therefor, it is impossible to combine the monitoring system disclosed in the Patent Literature 2 with the nurse call system disclosed in the Patent Literature 1.
Supposing that the nurse call system disclosed in the Patent Literature 1 and the monitoring system disclosed in the Patent Literature 2 can be combined together, an erroneous determination is likely to be undesirably made in the resulting system, because the monitoring system disclosed in the Patent Literature 2 is configured to determine an abnormal state of the target body only or mainly based on the physiological signal although there is the description about using the acceleration meter or the inclination sensor for fall-over.
Although the Patent Literature makes mention of an optical sensor, this optical sensor is designed to detect light and dark of an environment in which the target body is located (present), i.e., is not an image sensor.
Further, in recent years, due to further aging of society, home medical care in which a medical staff visits a patient's home to provide medical care has been gradually increasing, and the number of households of an elderly person living alone has also been increasing. Therefore, it will become necessary to monitor such a patient or single-living person under medical treatment at home.